254 ' ' William Christopher Kraiiss 



which all the S5'mptoms point to disease of the ventral cornua 

 of the spinal cord. Sensory disturbances and vasomotor troub- 

 les, symptoms of neuritic processes, are entirely wanting. 



The pathological changes found in the atrophied muscles 

 in the myelopathic forms correspond to simple degenerative 

 atrophy. To the naked eye there is little to be seen save the 

 diminution in size, and the pale, pinkish hue of the fibers ; 

 to the touch, a soft, spongy feel, with occasional cord-like 

 prominences, instead of a firm, resistant mass. The entire 

 muscle, if carefully removed, will be found shorter than nor- 

 mal owing to the contraction of the interstitial connective 

 tissue. Under the microscope the condition is as follows : If 

 the atrophy is not too far advanced, the fibers retain their 

 normal appearance — transverse and longitudinal striation — 

 but are somewhat narrower. As the process advances, the 

 fibers split up into longitudinal fibrillae, or transversely into 

 discoid masses and then gradually disappear. In other cases 

 fatty and vitreous degeneration ma}^ occur, and the fiber then 

 has the appearance of a sheath containing a clear material 

 with some fat globules. The intensity of this process is not 

 the same throughout the muscle, patches of healthy fibers 

 may be found surrounded by others in different stages of 

 atrophy. Proliferative changes occur in the nuclei of the 

 muscular fibers, and may lead to a new cell growth within 

 the sarcolemma, replacing the contractile substance. Prolif- 

 eration of the interstitial tissue also occurs and to such an ex- 

 tent as to separate the neighboring fibers. The entire muscle 

 ma3% in fact, be converted into bands of connective tissue 

 with some fat globules interpo.sed between the separate layers. 

 (See Plate, fig. 2.) 



The true designation of muscular atrophy considered as a 

 morbid eiitily applies only to those affections in which pro- 

 gressive wasting of the muscles is the reigning symptom. As 

 such Erb's juvenile form may be taken as a type of those 

 atrophies in which no focal lesion has as yet been discovered 

 in the nerve centers, but the muscle has been regarded as the 

 seat of the disease. As varieties, or deviations, may be men- 

 tioned the facio-scapulo-humeral type of Landouzy and De- 

 jerine, and the pseudohypertrophic paralysis of Duchenne. 



